• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.8
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• pp.682-685
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• 2011

An engine oil sensor based on multiwall carbon nanotubes was fabricated with screen printing method. Since carbon nanotubes are generally intertwined, dispersion of the carbon nanotubes in the binding agent (ethyl cellulose, a-terpineol, frit) is a key factor for large yield of engine oil sensor. By conventional dispersion method, a hand-mill method, the maximum yield was 80% at most. However, we used the hand ultrasonic, in order to increase the yield of the sensors. As a results, our engine oil sensor fabricated by the screen printing method shows excellent yield rate of 97%, when we dispersed a paste by the hand ultrasonic method.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.339-347
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• 2014

This study investigated the classification of olive oils that are mainly distributed in Korea via imports. The fatty acid contents, degree of color, pigments, anti-oxidants, and sterol contents are analyzed on the different types of olive oil as follows: 10 kinds of extra virgin olive oil, 5 kinds of pure olive oil, and 5 kinds of refined olive-pomace oil. As a result of fatty acid analysis, the majority of oleic acid ($C_{18:1}$) and palmitic acid ($C_{16:0}$), and minority of linoleic acid ($C_{18:2}$) and stearic acid ($C_{18:0}$) were detected without any significant differences between the grades of olive oils. The UV spectrum is related to the ${\Delta}K$, and it is a part of the analysis factor for the purity and degree of degradation of the oil. Extra virgin olive oil had ${\Delta}K$ of almost 0, pure olive oil had 0.07~0.12, and refined olive-pomace oil had 0.1~0.13. These differed from extra virgin oil, and the pure or pomace oil ${\Delta}K$ had a confirmed distinct difference. The color degrees of chlorophyll with a low $L^*$ value and $(-)a^*$ (green) and carotenoid with $(+)b^*$ (yellow) were confirmed to have correlation between extra virgin and other olive oils. To compare chlorophyll and carotenoid as natural pigment in olive oils, 417 nm and the ratio of the absorbance at 480 nm (417/480) was calculated at 1.62 of extra virgin, 1.85 of pure olive oil, and 3.32 of refined olive-pomace oil. Therefore, it will be possible to distinguish when the extra virgin or pure olive oil are mixed with olive-pomace oil. The total amount of tocopherol, an anti-oxidant, were 19.06 in extra virgin, 10.91 in pure olive oil, and 27.88 in refined olive-pomace oil. The high content of tocopherol in pomace oil caused recovery of solvent extraction from olive pulp. Thus, extra virgin oil and pure olive oil were distinguished by olive-pomace oil. Polyphenol compounds in extra virgin olive oil measured high only in ferulic acid with 0.543 mg/kg, caffeic acid with 0.393 mg/kg, and other vanillic acid, vanillin, and p-coumaric acid had similar amount of 0.3 mg/kg. All grade of olive oils had the highest ${\beta}$-sitosterol content. Af (Authenticity factor) value were estimated with campesterol and stigmasterol content ratio (%). Af value was 19.2 in extra virgin olive oil, 17.1 in pure olive oil, 16.9 in refined olive-pomace oil, which were distinctive from sunflower oil with 3.7, corn oil with 2.4, and soybean oil with 2.0. It can provide important indicator of olive oil adulteration with other cheap vegetable oils. The results of this study can be used as a database for the classification of olive oil grade and distinguishing between the different types of oils.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.6
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• pp.865-871
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• 2016

The objective of this study was to investigate the effects of canola and flaxseed oils on the physicochemical properties and sensory quality of emulsion-type sausage made from spent layer meat. Three types of sausage were manufactured with different fat sources: 20% pork back fat (CON), 20% canola oil (CA) and 20% flaxseed oil (FL). The pH value of the CA was significantly higher than the others (p<0.05). The highest water holding capacity was also presented for CA; in other words, CA demonstrated a significantly lower water loss value among the treatments (p<0.05). CA had the highest lightness value (p<0.05). However, FL showed the highest yellowness value (p<0.05) because of its own high-density yellow color. The texture profile of the treatments manufactured with vegetable oils showed higher values than for the CON (p<0.05); furthermore, CA had the highest texture profile values (p<0.05) among the treatments. The replacement of pork back fat with canola and flaxseed oils in sausages significantly increased the omega-3 fatty acid content (p<0.05) over 15 to 86 times, respectively. All emulsion sausages containing vegetable oil exhibited significantly lower values for saturated fatty acid content and the omega-6 to omega-3 ratios compared to CON (p<0.05). The results show that using canola or flaxseed oils as a pork fat replacer has a high potential to produce healthier products, and notably, the use of canola oil produced characteristics of great emulsion stability and sensory quality.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.655-658
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• 1994

This study was designed to investigate the suitability of oxidation matters and physico-chemical characteristics as a quality evaluation for the extent of rancidity development in fats and oils undergoing thermal oxidation. The results showed that acid value rapidly increased during heating time. Soybean oil, especially revealed a faster increase than palm oil and palm olein. Anisidine value and conjugated diene value also increased. Especially, soybean oil increased more rapidly than palm oil and palm olein. Active oxygen method stability was good in the ranks of palm oil, palm olein and soybean oil. Primary oxidation matter (POM) and secondary oxidation matter (SOM) were surveyed as an evaluation method for the extent of rancidity development in fats and oils. POM and SOM showed a sharp increase during the thermal oxidation period.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.696-700
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• 2010

Thirty-one units of pure rosemary essential oil (EO) in domestic and foreign distribution markets were collected. Aromatic components of these samples were analyzed and antioxidant activity was measured. As the result, major aromatic components were identified such as ${\alpha}$-pinene, camphene, ${\beta}$-pinene, 1.8-cineole, verbenone and borneol. Major components of rosemary EO were different according to countries. Essential oil from France had good quality. Essential oil cultivated and extracted in South Korea had more content than the collected essential oil in components of ${\alpha}$-pinene and camphene. Only 16% of the total 31 unit samples satisfied the content of 9 ingredients presented by ISO. The quality of EDA was shown as 4.8-96.0%, remarkable differences per specimen. A total of 31 units, only 13% of EO showed more than 60% antioxidant activity. Difference of antioxidant activity did not correspond with specific component. Essential oil from Swiss had high antioxidant activity.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.4
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• pp.330-336
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• 2017

This study performs a root cause analysis of the sticking that occurs in the hydraulically actuated wet type multi-disc friction clutch in a ship's diesel engine propulsion system that uses rubber elastic coupling. The fishbone method was used to study the sticking through dismantling investigation of the reduction gear and clutch, investigation of the components, and onboard system tests including nondestructive testing. The friction plate sticking is caused by the slip due to friction heat resulting from the leakage of control oil through cracks in the assembled hollow shaft. The friction plate cooling oil also leaks simultaneously through the crack, and partial sticking occurs due to the hot spots in the friction plates. These are caused by insufficient amount of cooling oil due to oil leakage.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.16-21
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• 2006

Effect of heat (160, 190, and $220^{\circ}C$ for 24 hr) on coconut oil was examined by principal component analysis using electronic nose consisting of six metal oxide sensors. Increase in heating temperature decreased ratio of resistance and first principal component score (from +0.952 to -0.325), indicating rancidity of coconut oil increased at high heating temperature. Result of electronic nose based on GC with surface acoustic wave sensor showed significant changes in volatile profiles of coconut oil. High resolution olfactory imaging $(VaporPrint^{TM})$ was particularly useful for evaluating oil quality. Peak numbers and areas increased with increasing heating time and temperature (160, $220^{\circ}C$). Electronic nose analysis can provide simple, fast, and straightforward results and is best suited for quality control and process monitoring in flavor field of food industry.

• Journal of Convergence for Information Technology
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• v.11 no.2
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• pp.211-218
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• 2021

The purpose of this study is to develop how to extract essential oil from heartwood of chamaecyparis obtusa and commercialize eco-friendly products using essential oil. Manufacturing process consisted of 8 steps: pulverization, input, pretreatment, extraction(steam distillation), steam emission, cooling, separation, aging. Through the method developed in this study, chamaecyparis obtusa oil with excellent quality in antibacterial effect can be extracted with high productivity. Also, chamaecyparis obtusa spray using this oil had good antibacterial and deodorant effects, and got no irritation results in the clinical test. To commercialize spray, we built a commercial website and performed consumer survey on the site. The survey results showed that respondents had positive attitude toward the products and their messages in the site. When the production standardization through precise quality control and the optimization of composition ratio are accomplished, this study will contribute to commercialize various types of cosmetics and quasi-drugs.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.99-103
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• 2021

This study was conducted to investigate the hatching rate of Pochazia shantungensis according to the treatment method of machine oil and the effect on apple quality by spawning. In the effect of machine oil treatment, when 20 times of the machine oil was spread by brush, the average hatching rate was 0.57%, and the sprayed branches showed an average hatching rate of 1%. When the machine oil agent was applied 50 times, the hatching rate was about 35% to spread by brush, whereas the spray treatment showed about 77%, so there were no difference from the non-treatment considering the deviation. There was no statistically significant difference in the quality of fruit even when apple fruits were fruited in the following year in the results of spawning and non-spawning of P. shantungensis in Hongro and Fuji varieties. In addition, there was no statistical significance in the difference between branch breakage and growth caused by spawning of P. shantungensis.

• The Korean Journal of Food And Nutrition
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• v.36 no.6
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• pp.479-488
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• 2023

In this study, quality properties of rapeseed oil by different roasting temperatures (140, 160, 180, and 200℃) were investigated. Roasted-pressed oil (RPO) showed a decrease in lightness and an increase in redness and yellowness with an increase in temperature compared to cold-pressed oil (CPO). In addition, the β-carotene and tocopherol content also increased in RPO as the roasting temperature increased. The tocopherol content increased by 18~20% in RPO at 200℃ compared to CPO. This increase in bioactive components led to improved radical scavenging activity dependent on roasting temperature, and RPO at 200℃ showed a 2.7-fold improvement compared to CPO. Finally, it was observed that higher roasting temperatures resulted in an extended oxidation induction period, increasing by up to 3.3 times. In conclusion, roasting is an effective method for enhancing the oil functionality of domestic rapeseed varieties. This study provides basic data for producing high-quality oil.